counting_bloom_filter.h

#ifndef CACHEMERE_COUNTINGBLOOMFILTER_H
#define CACHEMERE_COUNTINGBLOOMFILTER_H
 
#include <functional>
#include <vector>
 
#include <absl/hash/hash.h>
 
#include "hash_mixer.h"
 
namespace cachemere::policy::detail {
 
template<typename ItemHash> class CountingBloomFilter
{
public:
    CountingBloomFilter(uint32_t cardinality);
 
    template<typename ItemKey> void add(const ItemKey& item);
 
    void clear();
 
    void decay();
 
    template<typename ItemKey> [[nodiscard]] uint32_t estimate(const ItemKey& item) const;
 
    [[nodiscard]] uint32_t cardinality() const noexcept;
 
    [[nodiscard]] size_t memory_used() const noexcept;
 
    [[nodiscard]] double saturation() const noexcept;
 
private:
    uint32_t              m_cardinality;
    std::vector<uint32_t> m_filter;
    uint32_t              m_nb_hashes;
    uint32_t              m_nb_nonzero = 0;
};
 
}  // namespace cachemere::policy::detail
 
#include "counting_bloom_filter.hpp"
 
#endif